The pair were separated by just under three-tenths of a second but had a sizeable gap behind to the next competitor.
Guanyu Zhou was sixth ahead of early title favourite Nyck de Vries. Louis Deltraz was the lead Carlin, beating debutant Juan Manuel Correa to eighth place. Rounding out the top ten was the second Carlin of Nobuharu Matsushita.
There were no major dramas during the session other than Jack Aitken and Latifi getting very close at Turn 8, with Aitken seemingly unhappy after it appeared he was blocked by the Canadian.
Mahaveer Raghunathan spun late on in the session, but managed to avoid making any contact with the barriers.
Bahrain International Circuit - Winter testing
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